Fuel tanks may experience increased pressure during certain operating conditions. The increased pressure may be caused by an increase in the temperature in a sealed fuel tank. The duration that a fuel tank is sealed may be increased in hybrid vehicles using both an electric motor and an internal combustion engine for motive power when compared to vehicles relying solely on internal combustion engines for motive power. The increase may be due, in part, to the sporadic use of the internal combustion engine in the hybrid vehicle. Consequently, the pressure in a fuel tank of a hybrid vehicle may reach levels that are many times greater than those experienced in systems where the fuel tank is routinely purged to the engine whenever necessary. In some circumstances the pressure in a fuel tank of a hybrid vehicle may be 15-20 times greater than the maximum values experienced by a fuel tank in a vehicle relying solely on an internal combustion engine for motive power.
Thicker fuel tanks have been used to withstand the increased pressure within the fuel tank, such as heavier gauge metal fuel tanks However, the inventors herein have recognized various shortcomings of the above approach. For example, fuel tanks having increased wall thickness may not only increase vehicle costs, but may also increase the weight and size of the fuel tank. Moreover, the shape of the fuel tank housing may be selected based on the strength of the design rather than on the compactness of the design, thereby decreasing the compactness of the vehicle or the fuel tank's storage capacity. Consequently the vehicle's driving range may be decreased.
As such, various example systems and approaches are described herein. In one example, a distensible fuel tank included in a vehicle is provided. The distensible fuel tank includes a housing and a compliance structure coupled to the housing, the compliance structure including a support element coupled to a first side of a structural element and a reinforcing element coupled to a second opposing side of the structural element.
The compliance structure provides a desired amount of flexibility and strength to selected areas of the fuel tank. Specifically, the reinforcing element provides a greater amount of structural integrity to the fuel tank where desired. Additionally, structural characteristics of the compliance structure may be tuned to achieve specified fuel tank attributes. The geometric characteristics (e.g., width, length, etc.) of the reinforcing element may vary. In this way, the compliance structure may be tuned for a variety of fuel tank geometries, and therefore may be used across a wide range of fuel tanks As a result, the applicability of the fuel tank is increased, thereby reducing fuel tank production costs.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventors herein, and are not admitted to be known.